Communication links used for transmitting packets traditionally have a fixed amount of a single resource (e.g. bandwidth) available to be shared amongst competing packet flows. These packet flows are directed towards, or from, one or more end systems that are connected to an access router by said communications link. The packets are sent over the communications link in link-layer frames that may be considered to be different types of timeslots over the communications link. The communications link, and hence the timeslots over that communications link, are typically known apriori and therefore the system costs associated with the utilization of a number of timeslots is known in advance. Prior art communications links include those with multiple types of timeslots although each type of timeslot is still of a fixed size. The access router typically performs an accounting function that tracks either the number of timeslots utilized by an end system, or simply tracks the number and/or size of packets being delivered to, and received from, each end system. With a known fixed cost of timeslots, the number of data units employed by an end system, whether tracked as timeslots or packets, is sufficient for accounting purposes. Billing can then translate the accounting information into an end system bill by, for example, multiplying the number of data units by a charge per data unit. Other more sophisticated billing and accounting systems can take into the account different charging periods (e.g. dayrate v nightrate) and can also track the usage of differential service classes over the communications link bandwidth where said service classes are maintained by a scheduling algorithm, and access to service classes managed by service profiles for each end system as well as admission control algorithms for the communications link. Once again though, prior art systems track the amount of resource utilized in each service class, and the billing system translates that usage into a billable amount via a specific service class charge.
Novel communications links are being developed in which there are multiple fundamental link resources that need to be tracked, and for which the cost of the utilizing each resource can be very dynamic. Wireless links have dynamic capacities that fluctuate over time and space, with the number, location and movement of end systems in a cell, and in neighbouring cells, that are actively attempting to communicate at the same time. Wireless links have constraints on transmission levels due to battery capacity, interference generation and regulatory constraints. In addition, transmission energy also needs to be shared across multiple carriers and between communications link signaling and end system packet transport. Different transmission levels in different timeslots create different timeslot capacities. Further, different types of packets of the same size can incur very different load on the communications link. None of these, and other effects described in their application, are today tracked and fed into the accounting and billing systems. Aggregated system cost information is typically generated in the management plane, which whilst sufficient for long term dimensioning of capacity and even rough selection of charging levels for data unit transmission, is not sufficient for tracking and/or determining the dynamic cost per end system of delivered service.